Fully-degradable Heat-Insulating Environment-friendly Packaging Bag for Express Delivery

ABSTRACT

A fully-degradable heat-insulating environment-friendly packaging bag for express delivery, comprising a bag body, wherein the bag body has double fabric layers, including an inner layer of hot-rolled non-woven fabric, an outer layer of coated non-woven fabric, and a sandwich layer wherein the sandwich layer is filled with heat-insulating fibers. The bag body is using PLA biodegradable plastic material as base material, and the bag body is produced by spinning PLA, manufacturing thin non-woven fabrics, coating non-woven fabric, printing, forming a bag, and filling the fibers.

This application claims priority to Chinese Patent Application Ser. No.CN201811175132.2 filed on 10 Oct. 2018.

TECHNICAL FIELD

The present invention relates to a packaging bag, in particular to afully-naturally-degradable packaging bag.

BACKGROUND ART

A heat-insulating environmentally-friendly packaging bag for expressdelivery, is made from a fully-biological-based new plastic material byvarious molding techniques, avoiding the traditional use ofnon-environmental materials such as wood-based and petroleum-basedmaterials, popularization. And use of this application can effectivelyreduce the consumption of wood and petrochemical materials, prevent theimbalance of natural ecosystem and the pollution and destruction ofchemical materials to the environment.

Polylactic acid (PLA) is a new biodegradable material, made from thestarch raw material extracted from the renewable plant resources (suchas corn). The starch raw material is made into a lactic acid by the wayof fermentation, and then is converted to polylactic acid by the way ofchemical synthesis. It has an excellent biodegradability, and can becompletely degraded by microorganisms in nature after use, finallyproduces carbon dioxide and water, which do not pollute the environment,and it is very benefit to protect the environment, known as anenvironmentally friendly material. Publication number CN105416797Bdisclosed a biodegradation packaging bag for express delivery, which ismade of a composite coating, wherein the composite coating comprises afirst layer, a third layer and a second layer between the first layerand the third layer. The first layer, the third layer and the secondlayer are respectively made of coating material A or coating material B;the coating material A, by weight percentage, is composed of thefollowing components: 95.5% of polylactic acid, 3% of degradable colormasterbatch, 1.5% of tackifier; the coating material B, by weightpercentage, is composed of the following components: 95% ofpolyadipate/butylene terephthalate, 3.5% of degradable colormasterbatch, 1.5% of a tackifier. The invention further disclosed athree-layer co-extrusion-blown molding technology of the biodegradationpackaging bag for express delivery. According to the invention, the rawmaterial is easy to obtain with low production cost, is convenient toprocess, having an excellent processability, mechanical property andlow-temperature resisting tenacity, is suitable for the packagingindustry for express delivery, and it is biodegradable under the compostcondition, to solve the problem about environmental pollution caused byconsumption of a disposable express delivery packaging bag.

At present, degradable material is mainly made in the form of coatedbags. The shaping auxiliary materials such as tackifiers,compatibilizers are unavoidably added in manufacturing. In order to sealthe packaging bag, stickers, zippers and self-sealing strips are neededto be added, however, these auxiliary materials are difficult todegrade, or high in cost. The stickers, zippers and self-sealing stripsleft on the bags are always not easily degradable, could not achievereal full degradation.

DISCLOSURE OF INVENTION

The technical problem to be solved by the present invention is toprovide a fully-degradable heat-insulating environmentally-friendlypackaging bag for express delivery for above prior art, especially apackaging bag with degradable zippers, which simplifies the rawmaterial, and achieves the rapid full degradation of the packaging bag.

The technical solution adopted by the present invention is: afully-degradable heat-insulating environmentally-friendly packaging bagfor express delivery, comprising a bag body, wherein the bag body hasdouble fabric layers, including an inner layer of hot-rolled non-wovenfabric, an outer layer of coated non-woven fabric, and a sandwich layerwherein the sandwich layer is filled with heat-insulating fibers. Thebag body is using PLA biodegradable plastic material as base material,and the bag body is produced by spinning PLA, manufacturing thinnon-woven fabric, coating non-woven fabric, printing, forming a bag, andfilling the fibers.

The packaging bag for express delivery is produced by followingprocesses:

(1) spinning PLA, wherein spinning-grade PLA slices are used as rawmaterials to prepare PLA fibers, including melt spinning using ascrew-type spinning machine, and the melting point of PLA is 175° C.,and a spinning box is using a heating medium with a low boiling point sothat it is suitable for PLA, comprising following detailed steps: dryingthe raw materials until that a water content is less than 30 ppm,setting a screw pre-melting temperature to be 195˜210° C., setting ascrew outlet temperature to be 200˜215° C., setting a spinning headtemperature to be 200˜210° C., cooling, winding, cutting into sections,and then obtaining PLA short fibers;

(2) manufacturing thin non-woven fabric, wherein PLA short fibers areused as raw materials, and a hot-rolled non-woven fabric equipment isused, including following steps: carding PLA fibers, feeding fiberspneumatically, spreading fibers using a vibrating screen, hot rollingwith a couple of rollers, and then forming non-woven fabric;

(3) coating non-woven fabric, wherein the outer surface of some thinnon-woven fabric is coated, and PBAT material is used for the coating,including placing pure PBAT slices into a hopper of a coating machine,into a extruding screw and then forward to a coating die according todesignated levels of temperatures, wherein the temperatures of the screwand the die are controlled by a PLC controller of the coating machine,so that temperature control, die extrusion volume and non-woven fabricspeed match with one another, wherein the thickness of the coating iseffectively controlled to be 20˜60 g/square meter, preferable 40g/square meter, and then cooling by a cooling drum;

(4) printing, including printing on the coated layer of the non-wovenfabric;

(5) forming a bag, so that a bag body with a filling hole on its side isformed;

(6) filling fibers, wherein PLA fibers are used as heat-insulatingfibers and are filled into the sandwich layer of the bag body, includingmaking PLA fibers fluffy, automatically suctioning the fibers into afilling machine, aligning the filling hole of the bag body with afilling outlet of the filling machine, quantitatively filling thefibers, sealing the filling hole, and obtaining a finished product of aheat-insulating bag.

The bag body is being sealed by a zipper, the zipper's chain body andslider are made of composite materials of PLA and PBAT. In order toachieve full-degradation, as a part of the bag body, the zipper isrequired to be degradable, but the experiment finds that, using pure PLAcan not match the production mode of zipper and is difficult to beapplied in zipper production, the present application uses PBAT tomodify PLA, wherein the chain body of the zipper is made of a mixture of20% PLA+80% PBAT, the temperatures of extruder screw for the zipper areset to be 125° C. (feeding inlet), 135° C., 140° C., 145° C., 150° C.(discharge outlet). The slider of the zipper is made of a mixture of 50%PLA+50% PBAT or a mixture of 50% PLA+50% PBS, it is produced byinjection molding using an injection molding machine, and thetemperatures of screw are set to be 130° C. (feeding inlet), 150° C.,160° C., 170° C., 180° C. (nozzle), and a draft angle of an injectionmould is so designed as to be greater than 5 degrees because of a highviscosity of material. Otherwise, it might be difficult to demould.

The above chain body of the zipper achieves a hardness required for use,the hardness of the slider is larger than that of the chain body, thehardness of the slider in present application achieves a hardnesssimilar to PE and PP.

Preferably, in the step (1), the PLA short fibers are 4D fibers asheat-insulating material. This material is especially outstanding in theaspect of fluffy degree, and has a good heat-insulating effect.

Preferably, in the step (3), the screw is provided with six levels oftemperatures, which are 160° C., 190° C., 200° C., 223° C., 223° C.,223° C. in sequence, and the temperature of die is set to be 223° C.

Because PBAT has a strong viscosity, a normal coating machine is likelyto have a phenomenon that the coating is being bonded to the coolingdrum. The cooling drum in our step (3) is equipped with a contact layerof polytetrafluoroethylene on its surface, the surface of the coatingcontacts the contact layer of polytetrafluoroethylene of the coolingdrum to reduce the bonding between the coating and cooling drum,meanwhile, in combination with the adjustment of the extruder screwtemperature of the coating machine, it effectively avoids the occurrenceof the coating surface being bonded to the cooling drum.

As to the bag body being sealed by a zipper, the bag body is formed by anon-woven zipper bag making machine, with following steps: feedingdouble layers of non-woven fabric, automatically welding a zipper onboth sides by ultrasonic, folding, automatically installing a slider ofzipper, heating by ultrasonic, and cutting into bags, wherein a fillinghole is left on a side of a bag.

Compared with the prior art, the advantages of present invention are:

1) The heat-insulating environmentally-friendly packaging bag forexpress delivery in present application is using biodegradableplasticity materials such as PLA as base materials, and is produced byspinning PLA, manufacturing thin non-woven fabrics, coating non-wovenfabric, printing, forming a bag, and filling the fibers (PLA fibers);PLA is obtained by extracting and polymerizing the annual grain, thematerial character determines a sustainable regeneration and return tonature through microbial degradation in water.

2) The heat-insulating environmentally-friendly packaging bag forexpress delivery, in order to ensure high purity of degradablematerials, is free of adding any harmful chemicals in manufactureprocess, which adopts a technique of hot fusion ultrasonic fusion,avoids adding non-degradable auxiliary materials, and achieves a fulldegradation in real sense.

3) The material itself is sustainably recyclable, the source of rawmaterial is environmentally-friendly.

4) The packaging bag is using PLA short fibers as filling fibers,belonging to a kind of high-voidage fiber material. They are safe andsanitary when being filled in the sandwich layer.

MODE(S) FOR CARRYING OUT THE INVENTION

The present invention is further described in detail with reference tothe embodiments.

Embodiment 1

A fully-degradable heat-insulating environmentally-friendly packagingbag for express delivery, comprising a bag body, the bag body has doublefabric layers, including an inner layer of hot-rolled non-woven fabric,an outer layer of coated non-woven fabric, and a sandwich layer whereinthe sandwich layer is filled with heat-insulating fibers. The bag bodyis using PLA biodegradable plastic material as base material, and thebag body is being sealed by a zipper, the zipper's chain body and sliderare made of composite materials of PLA and PBAT.

The above packaging bag is produced by spinning PLA, manufacturing thinnon-woven fabric, coating non-woven fabric, printing, forming a bag, andfilling the fibers. The packaging bag is produced by following steps:

(1) spinning PLA, spinning-grade PLA slices are used as raw materials toprepare PLA fibers, including melt spinning using a screw-type spinningmachine, wherein the melting point of PLA is 175° C., and a spinning boxis using a heating medium with a low boiling point so that it issuitable for PLA, comprising following detailed steps: drying the rawmaterials until that a water content is less than 30 ppm, setting ascrew pre-melting temperature to be 200° C., setting a screw outlettemperature to be 215° C., setting a spinning head temperature to be200° C., cooling, winding, cutting into sections, and then obtaining PLAshort fibers;

(2) manufacturing thin non-woven fabrics, PLA short fibers are used asraw materials and a hot-rolling non-woven fabric equipment is used,including following steps: carding PLA fibers, feeding fiberspneumatically, spreading fibers using a vibrating screen, hot rollingwith a couple of rollers, and then forming non-woven fabric;

(3) coating non-woven fabric, the outer surface of some thin non-wovenfabric is coated, and PBAT material is used for the coating, includingplacing pure PBAT slices into a hopper of a coating machine, into aextruding screw and then forward to a coating die according todesignated levels of temperatures, wherein the temperatures of the screwand the die are controlled by a PLC controller of the coating machine,the screw is provided with six levels of temperatures, which are 160°C., 190° C., 200° C., 223° C., 223° C., 223° C. in sequence, and thetemperature of die is set to be 223° C., the non-woven fabric speed isset to be 50 g/square meter so that the thickness of the coating iseffectively controlled to be 40 g/square meter, and then cooling by acooling drum;

(4) printing: including printing on the coated layer of the non-wovenfabric, the coating can not only prevent water permeability ofheat-insulating bag but also enhance the artistic effect of surfaceprinting;

(5) forming a bag, so that a bag is formed by a non-woven zipper bagmaking machine, including following steps: feeding double layers ofnon-woven fabric, automatically welding a zipper on both sides byultrasonic, folding, automatically installing a slider of the zipper,heating by ultrasonic, and cutting into bags, wherein a filling hole isleft on a side of a bag.

(6) filling fibers, PLA fibers are used as heat-insulating fibers andare filled into the sandwich layer of the bag body, including making PLAfibers fluffy, automatically suctioning the fibers into a fillingmachine, aligning the filling hole of the bag body with a filling outletof the filling machine, quantitatively filling the fibers, sealing thefilling hole, and obtaining a finished product of a heat-insulating bag.

The above chain body is made of a mixture of 20% PLA+80% PBAT, and thetemperatures of extruder screw for the zipper are set to be 125° C.(feeding inlet), 135° C., 140° C., 145° C., 150° C. (discharge outlet).The slider of the zipper is made of a mixture of 50% PLA+50% PBAT or amixture of 50% PLA+50% PBS, and it is produced by injection moldingusing an injection molding machine, and the temperatures of screw areset to be 130° C. (feeding inlet), 150° C., 160° C., 170° C., 180° C.(nozzle), and a draft angle of an injection mould is so designed as tobe 5 degrees because of a high viscosity of material.

In order to prevent the bonding between the coating surface and thecooling drum, the cooling drum is equipped with a contact layer ofpolytetrafluoroethylene on its surface, the surface of the coatingcontacts the contact layer of polytetrafluoroethylene of the coolingdrum during cooling.

Embodiment 2

A fully-degradable heat-insulating environmentally-friendly packagingbag for express delivery is made by spinning PLA, manufacturing thinnon-woven fabric, coating non-woven fabric, printing, forming a bag, andfilling the fibers. The packaging bag is produced by following steps:

(1) spinning PLA, spinning-grade PLA slices are used as raw materials toprepare PLA fibers, including melt spinning using a screw-type spinningmachine, wherein the melting point of PLA is 175° C., and a spinning boxis using a heating medium with a low boiling point so that it issuitable for PLA, comprising following detailed steps: drying the rawmaterials until that a water content is less than 30 ppm, setting ascrew pre-melting temperature to be 210° C., setting a screw outlettemperature to be 200° C., setting a spinning head temperature to be210° C., cooling, winding, cutting into sections, and then obtaining PLAshort fibers;

(2) manufacturing thin non-woven fabrics, PLA short fibers are used asraw materials and a hot-rolling non-woven fabric equipment is used,including following steps: carding PLA fibers, feeding fiberspneumatically, spreading fibers using a vibrating screen, hot rollingwith a couple of rollers, and then forming non-woven fabric;

(3) coating non-woven fabric, the outer surface of some thin non-wovenfabric is coated, and PBAT material is used for the coating, includingplacing pure PBAT slices into a hopper of a coating machine, into aextruding screw and then forward to a coating die according todesignated levels of temperatures, wherein the temperatures of the screwand the die are controlled by a PLC controller of the coating machine,the screw is provided with six levels of temperatures, which are 160°C., 190° C., 200° C., 223° C., 223° C., 223° C. in sequence, and thetemperature of die is set to be 223° C., the non-woven fabric speed isset to be 50 g/square meter so that the thickness of the coating iseffectively controlled to be 40 g/square meter, and then cooling by acooling drum;

(4) printing, including printing on the coated layer of the non-wovenfabric, the coating can not only prevent water permeability ofheat-insulating bag but also enhance the artistic effect of surfaceprinting;

(5) forming a bag, so that a bag is formed by a non-woven zipper bagmaking machine, including following steps: feeding double layers ofnon-woven fabric, automatically welding a zipper on both sides byultrasonic, folding, automatically installing a slider of the zipper,heating by ultrasonic, and cutting into bags, wherein a filling hole isleft on a side of a bag.

(6) filling fibers, PLA fibers are used as heat-insulating fibers andare filled into the sandwich layer of the bag body, including making PLAfibers fluffy, automatically suctioning the fibers into a fillingmachine, aligning the filling hole of the bag body with a filling outletof the filling machine, quantitatively filling the fibers, sealing thefilling hole, and obtaining a finished product of a heat-insulating bag.

The above chain body is made of a mixture of 20% PLA+80% PBAT, and thetemperatures of extruder screw for the zipper are set to be 125° C.(feeding inlet), 135° C., 140° C., 145° C., 150° C. (discharge outlet).The slider of the zipper is made of a mixture of 50% PLA+50% PBAT or amixture of 50% PLA+50% PBS, and it is produced by injection moldingusing an injection molding machine, and the temperatures of screw areset to be 130° C. (feeding inlet), 150° C., 160° C., 170° C., 180° C.(nozzle), and a draft angle of an injection mould is so designed as tobe 5 degrees because of a high viscosity of material.

In order to prevent the bonding between the coating surface and thecooling drum, the cooling drum is equipped with a contact layer ofpolytetrafluoroethylene on its surface, the surface of the coatingcontacts the contact layer of polytetrafluoroethylene of the coolingdrum during cooling.

Performance test data of Embodiment 1 and 2 are shown in below table

Permeability Tensile Property Tear Property GB/T1037-1988 BS EN ISO13934-2: 2014 BS EN ISO 13937-1: 2000 Object PLA Thin Non- PLA Thin Non-PLA Thin Non- Bag Body wovne Fabric Bag Body woven Fabric Bag Body wovenFabric Unit Test Method g · m⁻² · d⁻¹ WARP/N WEFT/N WARP/N WEFT/N WARP/NWEFT/N WARP/N WEFT/N Embodiment 1 309 867 50 40 30 40 3.2 3.9 7.4 4.3Embodiment 2 313 866 52 41 30 43 3.3 3.9 7.6 4.4

The raw material of present application is very simple, free of additionof any other chemicals. By optimizing the technique design, afully-degradable packaging bag with a single raw material is obtained inreal sense.

Besides above embodiments, the present invention also includes otherembodiments, and any technical solution formed by equivalenttransformation or equivalent substitution shall fall within the scope ofprotection of the claims of the present invention.

What is claimed is:
 1. A fully-degradable heat-insulatingenvironment-friendly packaging bag for express delivery, characterizedin comprising a bag body, wherein the bag body has double fabric layer,including an inner layer of hot-rolled non-woven fabric, an outer layerof coated non-woven fabric, and a sandwich layer wherein the sandwichlayer is filled with heat-insulating fibers, wherein the bag body isusing PLA biodegradable plastic material as base material, and the bagbody is produced by spinning PLA, manufacturing thin non-woven fabric,coating non-woven fabric, printing, forming a bag and filling thefibers.
 2. The fully-degradable heat-insulating environment-friendlypackaging bag for express delivery according to claim 1, wherein thepackaging bag is produced by following processes: (1) spinning PLA,wherein spinning-grade PLA slices are used as raw materials to preparePLA fibers, including melt spinning using a screw-type spinning machine,wherein the melting point of PLA is 175° C., and the spinning box isusing a heating medium with a low boiling point so that it is suitablefor PLA, comprising following detailed steps: drying the raw materialsuntil that a water content is less than 30 ppm, setting a screwpre-melting temperature to be 195˜210° C., setting a screw outlettemperature to be 200˜215° C., setting a spinning head temperature to be200˜210° C., cooling, winding, cutting into sections, and then obtainingPLA short fibers; (2) manufacturing thin non-woven fabrics, wherein PLAshort fibers are used as raw materials, and a hot-rolled non-wovenfabric equipment is used, including following steps: carding PLA fibers,feeding fibers pneumatically, spreading fibers using a vibrating screen,hot rolling with a couple of roller, and then forming non-woven fabric;(3) coating non-woven fabric, wherein the outer surface of some thinnon-woven fabric is coated, and PBAT material is used for the coating,including placing pure PBAT slices into a hopper of a coating machine,into a extruding screw and then forward to a coating die according todesignated levels of temperatures, wherein the temperatures of the screwand the die are controlled by a PLC controller of the coating machine,so that temperature control, die extrusion volume and non-woven fabricspeed match with one another, wherein the thickness of the coating iseffectively controlled to be 20˜60 g/meter square, and then cooling by acooling drum; (4) printing, including printing on the coated layer ofthe non-woven fabrics; (5) forming a bag, so that a bag body with afilling hole on its side is formed; (6) filling fibers, wherein PLAfibers are used as heat-insulating fibers and are filled into thesandwich layer of the bag body, including making PLA fibers fluffy,automatically suctioning the fibers into a filling machine, aligning thefilling hole of the bag body with a filling outlet of the fillingmachine, quantitatively filling the fibers, sealing the filling holes,and obtaining a finished product of a heat-insulating bag.
 3. Thefully-degradable heat-insulating environment-friendly packaging bag forexpress delivery according to claim 1, wherein the bag body is beingsealed by a zipper, wherein the zipper's chain body and slider are madeof composite materials of PLA and PBAT.
 4. The fully-degradableheat-insulating environment-friendly packaging bag for express deliveryaccording to claim 3, wherein the chain body of the zipper is made of amixture of 20% PLA+80% PBAT, and the temperatures of extruder screw ofthe zipper are set to be 125° C. (feeding inlet), 135° C., 140° C., 145°C., 150° C. (discharge outlet).
 5. The fully-degradable heat-insulatingenvironment-friendly packaging bag for express delivery according toclaim 3, wherein the slider of the zipper is made of a mixture of 50%PLA+50% PBAT, or a mixture of 50% PLA+50% PBS, wherein it is produced byinjection molding using an injection molding machine, and thetemperatures of screw are set to be 130° C. (feeding inlet), 150° C.,160° C., 170° C., 180° C. (nozzle), and a draft angle of an injectionmould is so designed as to be greater than 5 degrees because of a highviscosity of material.
 6. The fully-degradable heat-insulatingenvironment-friendly packaging bag for express delivery according toclaim 2, wherein in the step (1), the PLA short fibers are 4D fibers asheat-insulating filling material.
 7. The fully-degradableheat-insulating environment-friendly packaging bag for express deliveryaccording to claim 2, wherein in the step (3), the screw is providedwith six levels of temperatures, which are 160° C., 190° C., 200° C.,223° C., 223° C., 223° C. in sequence, and the temperature of die is setto be 223° C.
 8. The fully-degradable heat-insulatingenvironment-friendly packaging bag for express delivery according toclaim 2, wherein in the step (3), the cooling drum in step (3) isequipped with a contact layer of polytetrafluoroethylene on its surface,wherein the surface of the coating contacts the contact layer ofpolytetrafluoroethylene of the cooling drum.
 9. The fully-degradableheat-insulating environment-friendly packaging bag for express deliveryaccording to claim 2, wherein the bag body is being sealed by a zipper,and is manufactured by a non-woven zipper bag making machine, with thefollowing manufacturing processes: feeding double layer of non-wovenfabric, automatically welding a zipper on both sides by ultrasonic,folding, automatically installing a slider of zipper, heating byultrasonic, and cutting into bags, wherein a filling holes is left on aside of a bag.